Nanoscale interface formation and charge transfer in graphene/silicon Schottky junctions; KPFM and CAFM studies

In this study, nanoscale interface formation and photogenerated carrier transfer in Schottky-junction between CVD graphene and n-Si wafer have been investigated using CAFM and KPFM techniques. The difference in the surface potential images of graphene observed on applying voltage between tip-graphene and tip-Si under light conditions has been understood in terms of holes transfer to graphene resulting in the shift of Fermi level and the open circuit voltage variations at the junction. A decrease in surface potential due to PMMA residues and an increase in surface potential near wrapping boundaries are the main reasons for the variation in photovoltaic parameters.